Conventionally, there have been known conveyance devices that carry out conveyed objects continuously supplied at a prescribed interval from a prior process to a subsequent process while changing the interval and a speed.
For example, when the outer peripheral surfaces of cylindrical cans in which a beverage or the like is to be filled are printed and coated, the outer peripheral surfaces of the cans are printed by ink in a printing process and then the ink and varnish are cured and fixed in a baking process.
The printing process allows the printing of the outer peripheral surfaces while conveying the cans at a high speed and at a prescribed interval, but the baking process requires a certain time. Therefore, in order to prevent the enlargement of a device, it is desirable to perform the printing process and the baking process while conveying the cans at a narrower interval and a lower speed.
In response to such a request, there have been known conveyance devices that have a turret that holds and conveys continuously supplied conveyed objects and a carrying-out conveyor that holds the conveyed objects and continuously carries out the same, and conveys the cans carried in the turret in a prior process to a subsequent process by the carrying-out conveyor while changing the conveyance speed of the cans and the interval between the cans during their conveyance (see, for example, PTL 1, 2, or the like).
In conveyance devices known in PTL 1 and 2, conveyance turrets (a transport wheel 27 and a transfer wheel 27) to which cans are continuously transferred from the carrying-out mechanism in a prior process (a printing process) have an interval adjustment mechanism that changes the radial positions of the held cans according to its rotation angle.
The conveyance turrets (the transport wheel 27 and the transfer wheel 27) reduces the radial positions of the respective cans during their rotations, and transfer the cans to a subsequent stage in two rows while alternately arranging the same at different radial positions.
In the conveyance device known in PTL 1, the subsequent stage represents a carrying-out conveyor (a deco chain) that holds the cans with pins 29 and carries out the same to a subsequent process, and the conveyance device is configured to transfer the cans from the conveyance turrets (the transport wheel 27 and the transfer wheel 27) to the carrying-out conveyor (the deco chain) in two rows and carry out the same to the subsequent process.
In the conveyance device known in PTL 2, a carrying-out turret (a conveyor plate 102) that sucks and holds the cans on its front surface is provided at the next stage of the conveyance turret (the transfer wheel 27), and the cans are transferred from the transfer turret (the transfer wheel 27) to the carrying-out turret (the conveyor turret 102) in two rows.
The carrying-out turret (the conveyor plate 102) is configured to convey the cans while holding the same in the two rows and transfer the cans to a carrying-out conveyor (a conveyor belt 105) remaining in the two rows, and the carrying-out conveyor (the conveyor belt 105) is configured to suck and hold the cans on its front surface and carry out the same to a subsequent process.